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According to the study of the soot emission in the combustion of diesel,a new reduced mechanism for n-Heptane was constructed to describe the combustion process in diesel engine by using sensitivity analysis.Furthermore,verifying the ignition delay time in combustion process by using CHEMKIN PRO in different pressure of 13.5 atm and 42 atm, initial temperatures of 600k and equivalence ratio of 0.5 and 1.0.Then,compare the simulated results with the experiment data, the mechanisms used in the simulation were Lawrence Livermore National Laboratory (LLNL) detail mechanism and the State Key Laboratory of Engine (SKLE) mechanism.

Currently, selective catalytic reduction (SCR) is one of the main after-treatment systems to control diesel engine NOx emission. But the SCR system is bulky, considering the limited installation space. Therefore, the design of SCR system with the compact structure and reliable performance is one of the essential topics. In this study, the structure parameters, such as catalyst cross-sectional area, catalyst length, substrate wall thickness, coating thickness, channels per square inch (CPSI) of substrate, are taken into consideration to study their effects on the SCR performance and narrow the scope of various structural parameters for the following optimization study. Then, the structural parameters of the SCR reactor are optimized by considering the coupling relationship among these structural parameters by using the Response Surface Methodology (RSM) at high load of diesel engine.

In this paper, the influences of metallic content of lubricating oils on diesel particles were investigated. Three lubricating oils with different levels of metallic content were used in a 2.22 Liter, two cylinders, four stroke, and direct injection diesel engine. 4.0 wt. % and 8 wt. % antioxidant and corrosion inhibitor (T202) were added into baseline lubricating oil to improve the performance respectively. Primary particle diameter distributions and particle nanostructure were compared and analyzed by Transmission Electron Microscope. The graphitization degrees of diesel particles from different lubricating oils were analyzed by Raman spectroscopy. Conclusions drawn from the experiments indicate that the metallic content increases the primary particles diameter at 1600 rpm and 2200 rpm. The primary particles diameter ranges from 5 nm to 65 nm and the distribution conformed to Gaussian distribution.

The aim of this research is to investigate the effects of ashless dispersant of lube oils on diesel exhaust particles. Emphasis is placed on particle size, morphology, nanostructure and graphitization degree. Three kinds of lube oils with different percentages of ashless dispersant were used in a two-cylinder diesel engine. Ashless dispersant (T154), which is widely used in petrochemical industry, were added into baseline oil at different blend percentages (4.0% and 8.0% by weight) to improve lubrication and cleaning performance. A high resolution Transmission Electron Microscope (HRTEM) and a Raman spectroscopy were employed to analyze and compare particle characteristics. According to the experiment results, primary particles diameter ranges from 3 nm to 65 nm, and the diameter distribution conformed to Gaussian distribution. When the ashless dispersant was used, the primary particles diameter decrease obviously at both 1600 rpm and 2200 rpm.